Die holding device in an indirect extrusion machine

ABSTRACT

A die in an indirect extrusion machine is secured to the stem of the machine at its free end through a die gripper secured to the free end of the stem by such means as screwing and the gripper is adapted to snugly receive the die without allowing it to shift axially.

United States Patent [191 Kishinn et al.

DllE HOLDING DEVTCE llN AN INDIRECT EXTRUSION MACll-llNE lnventors:Slaunji Kishino; Takahiro Abe, both of Muroran; Reishi 'lamura,Noboribetsu; liliroslii Ammo, Muroran, all of Japan Japan Steel WorlrsLtd, Tokyo, Japan Filed: Get. 31, 1972 Appl. No.: 302,507

Foreign Application Priority Data Assignee:

Nov. 25, 1971 Japan ..4694135 US. Cl 72/253, 72/253 A, 72/481 lnt. Cl.B2lc 23/00 Field 0i Search 72/481, 253, 254

References Cited UNITED STATES PATENTS 10/1960 Swanson 72/253 [1113,827,271 [45 1 Aug. 6, 1974 3,522,721 8/1970 Whiting ..72/2S5 3,541,83111/1970 Simomon ..72/253 Primary Examiner-Charles W. Lanham AssistantExaminer-Robert M. Rogers Attorney, Agent, or Firm-Wenderoth, Lind &Ponack [5 7] ABSTRACT A die in an indirect extrusion machine is securedto the stern of the machine at its free end through a die grippersecured to the free end of the stem by such means as screwing and thegripper is adapted to snugly receive the die without allowing it toshift axially.

5 Claims, 8 Drawing Figures PATENTEB W8 5 I974 3. 827, 2 7 1 FIG. 1PRIOR ART BACKGROUND OF THE INVENTION This invention relates to animprovement in an indirect extruding machine, and more particularly to adie holding device in the indirect extruding machine.

In an indirect metal extruding machine, it is necessary withoutexception to mount a die for extrusion at the forward end of theelongated hollow stem of the machine. Accordingly, it is conventionalthat, as shown in FIG. I, an elongated hollow stem 3a rigidly fixed atits base portion by a stem holder la and a stem stopper 2a mounts thedie 4a by inserting its projection in a recess provided at the forwardportion of the stem. However, in such a mounting means, the die must bedismounted from the stem every time the extrusion of a billet iscompleted in order to remove the unextruded butt of the billet, and itis also necessary to mount another die to the stem for the nextextrusion. For this procedure, in a small capacity extruding machine, itis usual to manually mount the die to the stem, but this is hard workwhich reduces productivity. Furthermore it also requires a number ofdies, which is uneconomic. Moreover, manual operation becomes difiicultas the capacity of an extruding machine becomes larger because theweight of the die becomes so heavy that manual mounting of the diebecomes difficult. Accordingly a die mounting apparatus is necessary.However, since such an apparatus is very large, being provided with agrip mechanism and a long arm to grasp the die, the cost of theequipment becomes high and if the apparatus breaks down productivity isseriously affected.

Alternatively, another die mounting means is known, as shown in FIG. 2,by which the stem 3a and the die 4a have corresponding formed screwthreads so that the die 4a is screwed to the stem 3a. This means isadvantageous in that the butt can be processed while the die 4a is stillmounted to the stem 311, so that interchanging of the die is no longernecessary. However, when it is necessary to interchange the die in orderto produce different extrusion products, since the temperatures of thedie 4a and the stem 30. are raised to 200 to 300C, the dismounting ofthe die is difficult so that it is necessary to wait until it coolsbefore the interchanging of the die can take place, resulting in a wasteof time. Further, when the screw thread of the die is damaged, itisimpossible to use the die, so that the life of the die may be shortened.As abovesaid, the hitherto known means for mounting a die to the stem ofthe indirect extrusion machine have many disadvantages, sonotwithstanding the fact that the indirect extrusion method hasbasically many advantages comparing with a direct extrusion method, anindirect extrusion machine embodying the former method has not yetgenerally been adopted in the art.

SUMMARY OF THE INVENTION It is an object of the present invention toprovide a die holding device in an indirect extrusion machine which caneliminate all of the disadvantages inherent to the conventional diemounting means as described above.

The die holding device of the present invention comprises a die gripmeans to be mounted to the stem of an indirect extrusion machine,whereby the die is mounted to the stem by securing the die to the diegrip means.

BRIEF DESCRIPTION OF THE DRAWINGS This and other objects of the presentinvention will become more apparent to those skilled in the art whenconsidered in reference to the following detailed description and inlight of the accompanying drawings, wherein:

FIG. I is an elevational, sectional view showing a conventional meansfor mounting the die to the stem of an indirect extruding machine;

FIG. 2 is an elevational partial sectional view showing anotherconventional means for mounting the die to the stem;

FIG. 3 is an elevational, sectional view of an embodiment of a dieholding device in accordance with the present invention;

FIG. 4 is a view similar to FIG. 3 showing an alternative embodiment ofthe present invention;

FIG. 5 is an elevational, sectional view of the die gripper shown inFIG. 3;

FIG. 6 is a side elevational view of the die gripper shown in FIG. 5;

FIG. 7 is an elevational, sectional view of the die gripper providing adie integrally in accordance with the present invention; and

FIG. 8 is an elevational, sectional view of the die gripper combinedwith a die in accordance with the present invention.

DESCRIPTION OF PREFERRED EMBODIMENTS As shown in FIG. 3, a hollow stem 3of an indirect extrusion machine is rigidly secured to the stern holder1 by a stem securing ring 2 at its tapered base portion, and a diegripper 5 is secured to the stem 3 at its forward end. In order tosecure the die gripper 5 to the stem 3, the gripper 5 is provided with ascrew thread 7 at the center of one of its end surfaces and a pipe 8,provided with threads at each end, is put through the hole of the hollowstem 3, whereby one of the threads of the pipe 8 is screwed to thethreaded end of the die gripping means, while the other of the threadsis screwed by a nut a to fasten the pipe 8 to the stem 3. In this case,pins 10 are provided at the free end of the hollow stem 3 for centeringthe die gripper 5. Otherwise, as shown in FIG. 4, the die gripper 5 maybe secured to the free end of the hollow stem 3 by screw threads 7'located on both of them. However, his preferable to secure the diegripper 5 to the hollow stem 3 by the pipe 8 to give it more strengthwhen it is desired to prevent the machining of the screw thread on thestem 3 because securing the die gripper to the pipe 8 makes it possibleto give a larger contact area between the hollow stem 3 and the diegripper 5, which increases the strength of the assembly.

Further, the die gripper 5 has a semi-circular projection 11 at itsforward end, as shown in FIGS. 5 and 6. This projection 11 engages in acircular groove 12 provided around the outer periphery of the die 4 asshown in FIG. 7 so that the axial displacement of the die 4 is preventedafter it is mounted to the die gripper 4.

The die 4 may have a solid construction as shown in FIG. 7, but, ininstances, where the shapes of the extruded objects vary frequently, acombined type die is preferable. This combined type die comprises a diering 13 similarly provided with a circumferential groove 12 at its outerperiphery as shown in FIG. 8, into which a changeable die 4 and diebacker 14 are inserted.

As explained above, according to the present invention, since a die canbe repeatedly used continuously, there is no need to mount the die everytime extrusion takes place as in the conventional means, and thepreparation of a plurality of dies is also not required, which makes thepresent invention economic.

Further, since the die can snugly fit the bottom curved surface of thedie gripper by the mere insertion of the die into the die gripper sothat the die is stably held by the gripper, mounting and dismounting ofthe die are very simple. Moreover, since no threading of the die for itsmounting to the stem is required, the need to discard the die because ofdamage of its threads is eliminated.

Further, when the die gripper is secured to the stem by means of thepipe passed through it, the stem is not required to be threaded so thatit has an advantageously long life.

In order to show the effect of the present invention with some figures,experiments were carried out using an indirect extruding machine havinga capacity of some 1,000t operating at an extrusion ratio of 90, withbillet dimension of 120 mm(diameter) X 600 mm(length) and usingaluminium of series of AA. 6,000 as the material to be extruded.

The results of the experiments are shown in the Table.

one cycle Note: In the above Table, A shows the results when the die wasmounted by the conventional means. and B shows the results when the diewas mounted through the die holding device according to the presentinvention,

It will be appreciated that, as shown in Table, by means of the dieholding device of the present invention, productivity is increased byabout 25 percent compared with the conventional die mounting means. Inaddition, since in the case of A, an operator exclusively engaged inmounting of die is necessary as well as a machine operator, the presentinvention has the advantage of requiring fewer operators.

While the invention has been shown and described with reference topreferred embodiments thereof it will be apparent that other changes andmodifications can be made in the present invention and therefore it isunderstood that all changes, equivalents, and modifications within thespirit and scope of the present invention are here meant to be includedin the appended claims.

What is claimed is:

1. In an indirect extruding machine having a stem holder, a stem securedat one end thereof to the stem holder and the stem having a threadedopposite end, the improvement comprising a hollow die grip member havinga threaded end and an end opposite thereto, said threaded end adapted tobe connected to said threaded opposite end of said stem and having asemicircular projection extending outwardly from said opposite end andhaving an inwardly extending lip at the end of said semicircularprojection, said hollow die grip member adapted to snugly receive acorresponding die within said semicircular projection.

2. In an indirect extruding machine having a stern holder, a sternsecured at one end thereof to the stem holder and the stem having athreaded opposite end, the improvement comprising a hollow die gripmember having a threaded end and an end opposite thereto, said threadedend adapted to be connected to said threaded opposite end of said stemand having a semicircular projection extending outwardly from saidopposite end and having an inwardly extending lip at the end of saidsemi-circular projection, and a die having a groove provided around theperiphery thereof adapted to engage said lip of said semi-circularprojecting, whereby said die is snugly supported within saidsemi-circular projection.

3. A die mounting device and die combination in an indirect extrudingmachine having a stem holder comprising: a hollow stem secured at oneend thereof to the stem holder of said indirect extruding machine; apipe member positioned within said hollow stern and having threadedopposite peripheral end portions, one end portion thereof being securedto said stem holder, the other end portion thereof extending beyond saidhollow stem; a hollow die grip member having one threaded end and anopposite end, said threaded end being connected to said extending end ofsaid pipe member, said hollow die grip member having a semicircularprojection extending outwardly from said opposite end and having aninwardly extending lip at the end of said semi-circular projection, saiddie grip member adapted to snugly receive a die within said semicircularprojection; and a die having a groove provided around the peripherythereof and adapted to engage said lip of said semi-circular projection,whereby said die is snugly supported therein.

4. The device of claim 3, further comprising a plurality of pinsconnected between said hollow die grip member and said stem forcentering said hollow die grip member relative to said stem and furthercomprising a bolster member adapted to be interposed between theopposite end of said hollow die grip member and said die.

5. A die for use in anindirect extruding machine having a stem holder, astem secured at one end thereof to the stem holder and the stem having athreaded opposite end, a threaded hollow die grip member having athreaded end and an end opposite thereto, said threaded end of said diegrip member adapted to be connected to said threaded opposite end ofsaid stem and said opposite end of said threaded hollow die grip memberhaving a semi-circular projection extending outwardly from said oppositeend and having an inwardly extending lip at the end of saidsemi-circular projection, said die comprising a body having a grooveprovided around the periphery thereof and adapted to engage said lip ofsaid semi-circular projection, whereby said die is snugly supportedtherein.

1. In an indirect extruding machine having a stem holder, a stem securedat one end thereof to the stem holder and the stem having a threadedopposite end, the improvement comprising a hollow die grip member havinga threaded end and an end opposite thereto, said threaded end adapted tobe connected to said threaded opposite end of said stem and having asemi-circular projection extending outwardly from said opposite end andhaving an inwardly extending lip at the end of said semicircularprojection, said hollow die grip member adapted to snugly receive acorresponding die within said semicircular projection.
 2. In an indirectextruding machine having a stem holder, a stem secured at one endthereof to the stem holder and the stem having a threaded opposite end,the improvement comprising a hollow die grip member having a threadedend and an end opposite thereto, said threaded end adapted to beconnected to said threaded opposite end of said stem and having asemi-circular projection extending outwardly from said opposite end andhaving an inwardly extending lip at the end of said semi-circularprojection, and a die having a groove provided around the peripherythereof adapted to engage said lip of said semi-circular projecting,whereby said die is snugly supported within said semi-circularprojection.
 3. A die mounting device and die combination in an indirectextruding machine having a stem holder comprising: a hollow stem securedat one end thereof to the stem holder of said indirect extrudingmachine; a pipe member positioned within said hollow stem and havingthreaded opposite peripheral end portions, one end portion thereof beingsecured to said stem holder, the other end portion thereof extendingbeyond said hollow stem; a hollow die grip member having one threadedend and an opposite end, said threaded end being connected to saidextending end of said pipe member, said hollow die grip membEr having asemi-circular projection extending outwardly from said opposite end andhaving an inwardly extending lip at the end of said semi-circularprojection, said die grip member adapted to snugly receive a die withinsaid semi-circular projection; and a die having a groove provided aroundthe periphery thereof and adapted to engage said lip of saidsemi-circular projection, whereby said die is snugly supported therein.4. The device of claim 3, further comprising a plurality of pinsconnected between said hollow die grip member and said stem forcentering said hollow die grip member relative to said stem and furthercomprising a bolster member adapted to be interposed between theopposite end of said hollow die grip member and said die.
 5. A die foruse in an indirect extruding machine having a stem holder, a stemsecured at one end thereof to the stem holder and the stem having athreaded opposite end, a threaded hollow die grip member having athreaded end and an end opposite thereto, said threaded end of said diegrip member adapted to be connected to said threaded opposite end ofsaid stem and said opposite end of said threaded hollow die grip memberhaving a semi-circular projection extending outwardly from said oppositeend and having an inwardly extending lip at the end of saidsemi-circular projection, said die comprising a body having a grooveprovided around the periphery thereof and adapted to engage said lip ofsaid semi-circular projection, whereby said die is snugly supportedtherein.